1. Field of the Invention
The present invention relates to a rotary connector device which is used in relatively rotating components to perform an electrical connection for control of an air bag device incorporated in a steering device for an automobile or control of an audio device or a constant speed traveling device by a switch button provided on a steering wheel for an automobile.
2. Description of the Related Art
As an example of this kind of rotary connector device, there is provided a device where a space is formed between a rotor coupled to a rotating steering shaft and a stator coupled to a vehicle fixed side, and a flat cable a winding direction of which is reversed in the halfway is accommodated in the space to be in a winding state. For example, according to Japanese Patent Laid-Open Publication No. 2010-3514, one end of this flat cable is fixed to the rotor side, and the other end is fixed to the stator side. The flat cable is reeled back from a cylindrical wall surface of the rotor corresponding to a rotating direction of the rotor to be wound around a cylindrical wall surface of the stator or reeled back from the cylindrical wall surface of the stator to be wound around the cylindrical wall surface of the rotor. This movement is repeated, so that an angular change between the rotor and the stator due to a relative rotation therebetween is absorbed by a change of the winding state of the flat cable. A spacer is arranged between the rotor and the stator for regulating a route of the flat cable.
However, the above conventional rotary connector device has a problem that sliding noises between the flat cable and the rotor or sliding noises between the case and the rotor are generated at the rotating of the steering shaft. For overcoming this problem, it is considered that an excellent material in sliding properties is used as a member of the rotor to reduce the sliding noise between the rotor and the flat cable at the rotating of the steering shaft. The excellent material in sliding properties, however, has a tendency of being insufficient in strength. As a result, as the excellent material in sliding properties is used in the rotor, it is difficult to ensure the strength of the rotary connector device.